Project Summary The long term objective of this SBIR application is to develop and test a minimum viable product (MVP) of Rock Steady, a software application for adults with vestibular dysfunction. This product is relevant to the mission of the NIDCD because it addresses the request for, ?the development of technologies for the study, diagnosis, and treatment of balance disorders, particularly for the elderly?. The envisioned product is an elegantly simple mobile application that is designed to measure adherence to a home exercise program of gaze stability exercises based on recommendations from the 2016 Clinical Practice Guidelines for Vestibular Rehabilitation. This product was conceived in response to four main drivers: 1) the growing number of adults aging with balance impairments due to vestibular dysfunction, 2) the finding that vestibular rehabilitation therapy (VRT) improves quality of life, 3) the need for developing engaging exercise programs that will improve adherence to VRT, and 4) a lack of commercially available low cost tools to support VRT. This application is very timely given the growth in the number of older adults and the ease of dissemination via smart tablets/PCs which are being adopted by older adults at faster rates than ever before. By deploying the app on common digital technology we will ensure its widespread adoption. Finally, it will be designed with end user feedback from all stakeholder groups including people with vestibular dysfunction. Broad Objective: We intend to translate existing evidence-based educational material, assessments and gaze stability exercises to a mobile device for widespread dissemination and adoption to increase adherence with home and clinic based VRT, promote health and wellbeing and improve patient care and outcomes through coordinated higher quality of care. Approach: In Phase 1 we will 1) employ user-centered design methodologies to develop and evaluate reliability, validity and usability of Rock Steady 1.0 for adults with vestibular dysfunction, over age 60, 2) integrate eye/head tracking and 3) identify and evaluate feature and content expansions/adaptations for Rock Steady 2.0. In Phase 2 we will employ user-centered, iterative design approaches to develop Rock Steady 2.0 and further feasibility, usability, and a pilot effectiveness study. Research Design: We will use a randomized trial design to evaluate reliability, validity and usability. All participants will complete two versions of standard evaluations of vestibular dysfunction using traditional paper/pencil method and via the app. Participants will be randomized to begin with either the app or traditional approaches. Reliability will be compared using interclass correlation coefficient, validity will be evaluated using Pearson/Spearman statistics and usability will be evaluated using the System Usability Scale questionnaire. Expected Outcomes: We believe that Rock Steady will be a valid and reliable adjunct to VRT. The app will provide healthcare professionals with important data regarding adherence, and function while also reducing the cost of care delivery.